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STRENGTHENING OCEANOGRAPHY | 65

GETTING TO KNOW ALDABRA
ATOLL BETTER

Several scientific programmes have been deployed in
one of the world's most extraordinary marine sanctua-
ries, one of the fifty marine sites listed as a UNESCO
World Heritage Site.

• Sentinel turtles
The implementation of the GECOS project during
the mission enabled the acquisition of additional
data essential to understanding the genetic struc-
ture of green and hawksbill turtle populations in
this region and developed indicators of the health
status of these species. Equipped with GPS bea-
cons, the individuals become veritable sentinels of
the island's ecology.

• Exploring small reef beds
How can we unravel the combined impacts of hu-
man activities on the coasts and climate change
on marine ecosystems in the western Indian
Ocean? The images and data collected by the
4Sea project's autonomous observation systems
Aldabra atoll
are currently being analysed to produce inventories © N.Mathys-Zeppelin-
of species and the nature of the seabed, and 3D MonacoExplorations
maps of the habitats explored.

• Successful coral sampling
The mission enabled the first samples to be taken
as part of the World Coral Conservatory, an initia-
tive supported by the Monaco Scientific Centre THE DISCOVERY OF NEW SPECIES AT SAYA DE MALHA
and the Oceanographic Institute: 58 colonies of
living coral representing 21 species were collected The photographic inventory and collection of organisms made it
and then transferred to the European aquariums possible to list:
responsible for their conservation. ■ almost 400 species of molluscs,
■ around 300 species of crustaceans,
• Coral: connected colonies? ■ around a hundred species of algae,
Do the atolls and the shoals in the central Indian ■ very probably 4 new species: 3 gastropod specimens
Ocean play a decisive role in the attraction and and 1 crustacean specimen not yet described by taxonomists,
biodiversity of corals and invertebrates in the eas-
tern and western basins? The programme led by ■ 2 emblematic species, the gastropod Conus primus, and the
the Zoological Society of London and the Univer- clam Tridacna rosewaterii rediscovered.
sity of Oxford focuses on the connectivity of coral
species in the Indian Ocean. The team sought to "Gigabytes of digital data on physico-chemical and biological
determine Aladabra's contribution to the resilience parameters measured by the bathysonde in the water column
of the region's corals and to find out whether the and long hours of video footage filmed by the ROV (remotely ope-
brain coral, endemic to the Chagos Archipelago, rated underwater vehicle) or various cameras sent down to the
was present at Saya de Malha. seabed were stored on the computers. This will provide a wealth
of research topics for our young researchers in the region. This
• A first for Aldabra valuable information on the properties of the water column and
The investigations carried out with the ROV (remo- the habitats visited gives context to the floristic and faunistic in-
tely operated underwater vehicle) on the slopes of ventory described above", comments Francis Marsac, head of the
the Aldabra reef to a depth of 700 metres pushed
back the limits of exploration of the site, which had project devoted to the Saya de Malha bank and representative of
previously not exceeded a depth of 250 metres. the Research Institute for Development, in the Seychelles.